I totally support the rights of anyone to pray anywhere they want, as long as they do it quietly and respectfully to those around them. These guys (see picture below) are doing just that. Hell, if I rushed into burning buildings for a living, I'd pray, too. If I saw these guys in the diner, I'd buy them dinner as a way of saying "thank you for being real life heroes."
Okay, back to the meme. The only problem I have is that this is loaded. The real agenda of this meme is to tweak Christians and exaggerate the sense of "Christians are persecuted." Which, in the US, they sure as Hell aren't.
Here is the litmus test to decide if you've been tweaked: Imagine these guys had brown skin and were on their knees on prayer mats. If that image bothers you, then your nose has been tweaked and your chain has been yanked, and maybe now you have an understanding of what it means to not be the "right kind of religion" in America.